-iewin



(No Model.)

. 2 Sheets-Shet 1. G; L. IRWIN. DRIER P03 WHITE LEAD AND OTHER MATERIALS. No. 288,574.

Patented Nov. 13, 1883.

2 SheetsSheet 2.

(No Model.)-

G. L. IRWIN.

DRIER FOR WHITE LEAD AND OTHER MATERIALS.

Patented Nov. 13, 1883.

r N v 7 H m N. PETERS. Pmwmho m vm. wnhinglm D. c.

llNirn STATES ATENT Fricn.

GEORGE LQIRWIN, F ALLEGHENY, PENNSYLVANIA, AssieNoR' TO HIMSELF AND R. L. one, onsAME PLACE.

DRIER FOR WHITE LEAD AND OTHER MATERIALS SPECIFICATION forming part of Letters Patent No. 288,574, dated November 13 1883.

Application filed March 10, 1883. (Nn model.)

Be it known that I, GEORGE L. IRWIN, of

Allegheny, in thecounty of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Driers for WVhite Lead and other Materials; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to the drying of white lead or other pulverulent or granular substances or materials, and has special reference to the drying of white lead during its treatment for the manufacture of paint, 'After the lead has been corroded, it is first crushed and then ground with water, to wash out the acid, and the water is then thoroughly dried out be fore it is chased in oil, and ground in oil to form the finished product. The only method of drying the lead heretofore generally employed is to spread it over large flat steamheated pans, each pan holding about five tons of lead, and gradually dry out the moisture,

the operation requiring seven or eight days, and the steam-heat being necessarily kept up day and night. These drying-pans are exceedingly expensive, and in an ordinary leadworks from six to twelve of these pans are required, and the time lost in drying the lead adds largely to the" expense of manufacture. It is also found that the lead cakes and forms lumps when drying, and for this reason it is neeessaryto chase the lead in oil before it is mixed and ground for use. For these reasons an eflicient and more rapid means of drying the lead is much sought for and the special object of my invention is to supply this need,

- though my improved drying apparatus may be employed for drying many other pulverulent or granular materials.

My invention consists, essentially, in the combination of a hollow heated trough or pan.

1 a hollowheatedpiperotated therein, and provided with a flight or equivalent means for feeding the materials to be dried through the trough, and hollow heated rolls for crushing and pulverizing the material during drying,

so that the lead is confined between the heated verized as it is delivered from the drying apthe flight or feeding apparatus, and'thehollow 6 a n heated rolls and their steam-connections.

To enable'others skilled in the art to make and use my invention, I will describe its contion and operation, referring to the accompa= nying drawings, in which 6 Figure l is a side view, partly brokeiraway, of my improved apparatus. Fig. 2 is a top view of the drying-trough and pipe, the wingflanges of the trough being removed. Fig. 3 is a cross-section of the drying-trough and pipe. Fig. 4. is a top view, partly broken away, of the crushing-rolls; and Fig. 5 is a longitudinal section of one of the crushing rolls.

Like letters of reference indicate like parts in each.-

The apparatus is supported in. the framework A, which is preferably formed of heavy vertical standards at each end, connected by cross-braces a, on which the troughs or pans .80 B and the housings c of the crushingrrolls O are supported.

The trough or pan B is formed of a castiron box, b,-and is generally about twenty-five feet long. The upper faces of the end plates of the box are semicircular, and the box is covered by the plate (I, thus forming the semi-cylindrical trough or pan within which the tube E is rotated. The plate d is secured to the box by the bolts 01 passing through the flanges go I) of the box I), and by riveting at the ends of the box, the pan being formed steam-tight.

The pipe or tube E is slightly smaller in diameter than the trough portion of the pan, and is provided with the worm, flight, or other 9 5 apparatus for conveying the material along the trough, the apparatus preferred by me be ing the worm orflight e, whichextends out from the pipe E and fits the trough portion of the pan neatly.

As it is necessary that the material to be dried be held in close contact with the heated roe vIO

surfaces of the drying apparatus, the flight e is shallow, being generally made about onehalf inch high. To hold the material within the trough, the pan is provided with the curved supplemental wing-flanges E, which fit closely to the flight e for a short distance, and then extend above the flight, the flanges being drawn together to preclude the escape of any material, and yet leave a space above for the escape of the steam evaporated from the material to be dried. The flanges F are secured to the braces f, and are secured to the trough by means of the bolts (1, which extend through the braces, flange-plates, trouglrplate, flanges b of the box I), securing them all firmly together, as shown in Fig. 3.

decreasing in height until they vanish at or near the next turn of the flight, and these wings will lift the lumps of lead or other material and carry them over the pipe, so that they necessarily pass between the heated faces of the trough and pipe. These wings g are made the same height as the flight for but part of the length, because they are only designed to lift the lumps which gather along the flight and run up it, and are not carried forward thereby. By eausing them to pass between the heated faces of the trough and pipe they are more rapidly dried, and thus fall apart.

The working-faces of the trough, pipe, and flight are preferably made of copper when used for drying lead; but for drying other materials, iron, steel, or other metal may be employed, according to the materials to be dried.

Steam is conducted to the trough-pan B for heating it through the pipe I) at oneend there of, and the water of condensation and exhauststeam passes out of the pan through the pipe If in the base of the pan at the opposite end, and from thence into the exhaust-pipe s. The pipe E is journaled in suitable bearings in the frame A, and is rotated by means of the pulley h, power being communicated from one pipe to another,wheremorethan one are used, through the gear-wheels h. The steam passes into the pipes E from the pipes at one end of the apparatus, being connected thereto by the swivel 7c, and it exhausts into the pipes l at the other end through the swivel l.

The supply-pipes 70 may be of any suitable size; but the exhaust-pipesl and their swivels must be of the same or greater interior diamcten than that of the pipes, to carry away all water of condensation, this being absolutely necessary, because the water would chill the lower face of the pipe, which comes-in contact with the material to be dried, and should be kept at as high a heat as possible.

In order to crush any lumps in the material as it is fed to the different pans, and finally from the apparatus, I employ the hollow rolls C, heated bysteam or in other manner. The rolls are mounted in housings 0, supported on the cross-braces a in such position as to receive the material from the vat or from the dryingpan, crush it, and deliver it into the pan below, any suitable chutes or guides being employed to direct the materials into the rolls and pans. As the rolls are most efficien tly heated by steam, I have illustrated the power and steam connections, their construction being particularly shown in Figs. 4: and 5. As the crushing-pressure on the rolls is slight, and they are required to be thin to permit the rapid passage of the heat from the steam, they are preferably formed of wrought metal, copper being usually employed, or the rolls having a sheathing of copper when employed with lead-drying apparatus. The rolls are journaled in the housings at their full diameter, and at one end are the necks m, carrying the band-pulleys or gear a, by which power is applied to the rolls. Beyond the pulleys are the swivels t, by which the steam-connections are made between the supply-steam pipe and the rolls. The other or exhaust ends of the rolls are connected by the swivels r with the steamboxes R in such manner that the interior face of the rolls and steam-boxes are even, so that all water of condensation can pass out of the rolls into the steam-box R, and from the steambox into the exhaust-pipe s, so that the rolls are not chilled thereby. I prefer to employ a pair of these heated rolls at the feeding end of the apparatus, to insure the crushing of all lumps of material to be dried, as it dries more quickly when in a pulverulent or finely-d} vided condition, and at the discharge end to crush any lumps which may have formed in drying.

The exact construction and arrangement of the different parts of the apparatus may, of course, be changed according to the material to be dried or location of the apparatus.

In drying lead by my improved apparatus I prefer to employ three or more of the dryingpans. The pans B, pipes E, and rolls 0 are heated by the steam passing through them, and the pipes and rolls are rotated at a slow speed. The lead is fed from the vat through the rolls 0 above the first pan, and, after being crushed thereby, passes into the trough of the pan B. As the flight c on the pipe E catches the lead it draws it forward in the trough, and as the lead is confined between the heated surfaces of the pan and pipe thebetween the wing-flanges F of the pan, andthese flanges holding the lead within the trough of the pan.

The flight on the pipe keeps the 5 I 5 thoroughly dried, and finally crushed as it leaves the last pan, and is delivered to the particles of lead in motion,turning it over, so that itis all brought into contact with the steam-heated surfaces of the pipe and pan. In

a case the lead forms into lumps in drying, these lumps have a tendency to run up the face of the flight without being fed forward thereby, and the wing g on the pipe then carries over these lumps, causing them to pass under between the pipe and trough in the hottest part of the adapted to carry over the lumps, allowing the flight to carry the particles of lead forward in the usual manner. The lead is thus carried forward betweenthe heated surfaces of the pan and pipe until it reaches the discharge end of the trough, from which it passes through the crushing-rolls G into the next pan, any lumps formed being crushed, and the material being delivered thereto in a pulverized or finely-divided form. i It is thus carried through as many pans as desired until it is proper bin or receptacle for grinding.

As the lead is kept in motion during the entire time of drying, and is prevented from caking or forming into lumps, as before described, it is delivered from the machine in such a finelydivided state that it can .be immediately ground in oil without the chasing heretofore considered necessary. The pipes B are turned very slowlyin the pans,so that their feeding action is slow and the lead is gradually dried, so that it is not subjected to such heat as would injure it. The process is,'however, much more rapid than the flat drying-pans heretofore employed, and one such apparatus, where the drying-pans are about twenty-five feet long, is adapted to dry from five to ten tons of lead per day, being sufficient for an ordinaryleadmanufactory.

In drying flour, clay, and other pulverulent materials in my improved apparatus it is employed in substantially the manner above described, the materials being crushed between the rolls after leaving each drying-pan, and delivered in a finely-divided condition. In drying grain and like substances the rolls are dispensed with, the substances passing from one pan directly to the other, where more than one pan is required.

During the operation of the apparatus all the water of condensation passes from the pipes and rolls into the exhaust-pipes on ac count of the peculiar construction of their swivel-connections, so that the steam can heat them over their entire surfaces, and there is no opportunity of this water chilling them.

WhatI claim as my invention, and desire to secureby Letters Patent, is-

1. In apparatus for drying lead and other ma terials, the combination, with a heated trough and heated pipe provided with a flight or equivalent feeding apparatus, of heated rolls for crushing the material during drying, substantially as set forth.

2. I11 drying apparatus, thecombination of two or more drying-troughs supported one above the other, and provided with heated pipes having feeding apparatus, with heated rolls so located as to receive the material from one trough, crush it. and deliver it to the next trough, substantially as and for the purposes set forth.

3. In drying apparatus, the combination, with the heated pip"e E, provided with feeding apparatus 6, ofthe heated trough or pipe B, provided with the curved supplemental flanges F, extending partially over the feeding apparatus in contact therewith, substantially as and for the purposes set forth.

4. In drying apparatus, the hollow rolls 0, so connected by means of a swivel with the steam-exhausts R that both the internal and external diameter of the rolls and exhausts are substantially the same, as and for the purposes set forth.

5. In drying apparatus, the combination, i 

